Backfire, high idle

PETE28

MEMBER
1984 CHEVROLET CAMARO
5.0L
V8
2WD
AUTOMATIC
100,000 MILES

Sometimes white smoke comes out of my carburetor. Not too often. Car runs good except for a hesitation here and there and wanting to stall out. It recently started backfiring and in the last backfire, the idle went up and it will not come down. The backfire was loud and it smelled like smoke. Note: recently I installed a refurbished computer controlled quadra jet carburetor because my previous carburetor was in need of work. I installed a new O2 sensor, new spark plugs, EGR valve, ignition wires, cap and rotor, and ignition coil. I ran out of options and the car it just feels bad. I suspect the timing chain because of the latest backfire. Please any help I would greatly appreciate it.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
43,057 POSTS

Hello,

Two things can mainly cause a backfire for your car, the first is the accelerator pump is not working which can be checked using a flash light with the air cleaner removed. While looking down into the carb open the throttle and your should see two small streams of fuel enter the engine. Do this test with the engine off.

Next would be the ignition timing is too far retarded and should be advanced about 4 degrees to make up for anny wear the timing chain has experienced.

Here is a guide that can help as well.

https://www.2carpros.com/articles/engine-backfires-while-running

Please let us know what happens.

Cheers, Ken